1. Field of the Invention
The present invention relates to a rear seat apparatus for a vehicle, and more particularly to a rear seat apparatus for a vehicle which is disposed on a floor surface on the rear side of the vehicle.
2. Description of the Related Art
Conventionally, a structure shown in Japanese Utility Model Application Laid-Open (JP-U) No. 3-125625 is known as an example of a rear seat apparatus for a vehicle which is disposed on a rear-side floor surface of the vehicle.
As shown in FIG. 19, the rear seat apparatus for a vehicle has a cam hole 72 and a peripheral cam 74 which are formed in each of a pair of brackets 70, as well as a pivot shaft 78 and a guide shaft 80 which are provided on a seat cushion 76. With respect to a floor surface 82, the rear seat apparatus permits the seat cushion 76 to be moved from a first position (the position shown in FIG. 19) in which the seat cushion 76 is held substantially horizontally, to a second position (the position shown in FIG. 20) in which the seat cushion 76 is made upright substantially vertically, and to a third position (not shown) in which the seat cushion 76 is turned over in the forward direction of the vehicle.
With this rear seat apparatus for a vehicle, however, as shown in FIG. 19, the seat cushion 76 is disposed on the floor surface 82 which is flat. Therefore, to improve the cushioning feature of the seat cushion 76, it is conceivable to make the seat cushion 76 thick, but if the seat cushion 76 is made thick, the weight of the overall seat cushion 76 becomes heavy, with the result that the operating efficiency when the seat cushion 76 is moved to each position deteriorates. In the case where the seat cushion 76 is made thick, in order to prevent the submarine phenomenon (i.e., the phenomenon in which the waist belt of the seat belt fitted to a vehicle occupant becomes dislocated from his or her pelvis portion) during a frontal collision, it is necessary to separately provide a submarine-phenomenon preventing member, resulting in a further increase in the weight.